Problem 2 a) Show that a(t) = ct is a solution of the Friedmann equations for a completely empty universe (p = p= 0) if k = -1. %3D b) Find expressions for the proper distance dp and the angular diameter distance da as functions redshift z for this model.

Q: 9 and 10. Thanks.

A: 9.The equation for dot product

Q: h power (E

A: Given: Surface area of Ashcraft is 1.9 m2 Emissivity is 1 Temperature is 37oC or 37+273=310 K

Q: B A coin sits on a rotating turntable as shown in the figure. At the time shown in the figure, which…

A: We need to say what the direction of friction will be on the coin on turntable.

Q: When laser light of wavelength 632.8nm passes through a diffraction grating, the first bright spots…

A: Given: In this question, the given details are, When the laser light of wavelength 632.8 nm passes…

Q: In the following diagram, the current passing through 20 Ohm is 1.5 A. 19. What is the current…

A:

Q: 7. Calculate the potential energy that another charge q2 = 5.00 µC possess when placed at the three…

A: The magnitude of charge is q = 5.00 uC = 5.00 x 10-6 C Distance a is r1 = 1.00 m Distance 2 is r2 =…

Q: Four equal +2.00-µC point charges are placed at the corners of a square 4.00 m on each side. (k =…

A:

Q: If each wire in #4 is connected to an identical battery, what is the relationship of the electric…

A:

Q: 1. Can objects in a system have momentum while the momentum of the system is zero? Explain.

A: Given :- can objects in a system have momentum while the momentum of the system is zero .

Q: from one end (see figure). There are pposite ends of the beam, where W, < W,. Find x such that the…

A: GivenW1=900 NW2=2700 N

Q: The total time a projectile spends in the air along its trajectory A. air resistance В. trajectory…

A: Answer is D

Q: 3. a quantity that describes the rate of motion in the y direction A. horizontal component of…

A: As we know that rate of motion is speed . But according to the question,  we have asked the rate of…

Q: A block (4 kg) starts from rest and slides down a frictionless ramp #1 of height 9 m. The block then…

A: Since you have posted multiple parts we will solve the first three parts for you, kindly post the…

Q: 4. Two charged metal spheres, separated by 20 cm, resulting force when the charge on each sphere is…

A:

Q: 2. Three point charges q; = +2.7µC, q2 = -3.4µC and q3 = -1.6µC initialy are infinitely far apart.…

A:

Q: Two infinite sheets of current flow parallel to the y-z plane as shown. The sheets are equally…

A: Given:Current through sheet at left, I1 = 2.9 (-k^) A in each wire Current through sheet at right,…

Q: 3. If V = 12 V in the circuit below R = 100 N R2= 200 N %3| R3 = 100 N R5= 300 N R4 = 150 N R, = 100…

A: Solution: Given that V = 12 V and the values of other resistors

Q: Problem #1) Determine the moment of forces about point 0. F3=75 lb X- 15⁰ 6'-0" Y F₂ = 50 lb 90° Y…

A: Forces F1 = 25 lb,  F2 = 50 lb, F3 =  75 lbdistance between origin and point O (d) = 6 ft

Q: If a person pushes on a lawnmower with a constant force of 90.0 N at an angle of 40° to the…

A: Given data: Constant force (F) = 90.0 N Angle (θ) = 40° to the horizontal Horizontal displacement…

Q: The block in the drawing has dimensions LO×2L0×3L0.where Lo =0.3 m. The block has a thermal…

A: Give Thermal conductivity = 100j/s-mC  Delta T = 21- 12 ° C = 9 ° c

Q: On earth, two parts of a space probe weigh 10600 N and 3780 N. These parts are separated by a…

A:

Q: = 201². The fan blade in a jet engine rotates from rest with the angular acceleration a = 1 9. find…

A: GIVEN         Angular acceleration = α = 20t2

Q: 4. When is the magnetic flux maximum? zero? 5. A loop of wire in the form of a square 1.50 m on each…

A:

Q: A conducting bar of length 0.25 m and mass of 0.34 kg is pulled to the right with a Force of 3.0 N.…

A: Write a given values of this question. L=0.25mm=0.34kgF=3.0NB=0.750TR=50Ω

Q: Using the letters, match each prefix with the multiplier it represents. V V V V x 10-6 x 106 x 10-3…

A: The given prefix are associated with multiplier as per their definition.

Q: And r0 ?

A:

Q: When two parallel plates connected to a 40-V battery, the electric field between the plates is 2200…

A: Given: In this question, the given values are, Voltage is, V=40Volt, And the electric field is,…

Q: 6&amp;7 please

A:

Q: 5) Let's use this expression to solve a problem. Star X and Star Y are intrinsically identical…

A: Given, star X is located 20 light-years from earth star Y is located 40 light-years  from earth…

Q: 3. We will repeat the previous problem using energy arguments. Comment: Mechanical energy is…

A: The given yo-yo is made up of two solid disks, each of mass M, so the total mass of the yo-yo is 2M.…

Q: 7. "The wider the road, the more cars can pass through". Which of the following factors affecting…

A: We need to tell which factor affecting the resistance fits the given analogy.

Q: 7. Solve for unknown parameters 30

A: solution is given as

Q: Consider the 68.0 kg mountain climber in the figure. 31 Fup 15 (a) Find the tension in the rope (in…

A:

Q: 7,8,9

A:

Q: 3. Determine whether the corresponding system is linear, time invariant and causal. Show block…

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Q: wave paths to a distant screen are shown, leaving the slits at angle ₁. (The screen is so far away…

A: The wavelength of light is 624 nm.  (1) Every semi circle wavelet represents a wave front. Wave 1…

Q: In a video clip, a man is bound by chains and is hanging from the top and rotating on the chain. In…

A: Scenario: A man is hanging from the top and bounded by a chain such that man is rotating on the…

Q: 12k R1 A 4k

A: HERE GIVEN I=24 mA     R1= 12k     R2  = 4k according to kirchhoffs law  JUNCTION LAW  incoming…

Q: At what speed, as a fraction of c, does

A:

Q: A coaxial cable filled with teflon carries a current of 0.75 Amps out of the page along the central…

A: The integral form of the original circuital law is a line integral of the magnetic field around some…